The survey of air freight and mail in commercial aviation (scheduled and non-scheduled) covers domestic and foreign aircraft which take off or land at the Austrian airports of Vienna, Graz, Innsbruck, Klagenfurt, Linz and Salzburg. Data is collected on the volume of air freight and mail on flights with passengers, freight and mail transport in domestic and international traffic where the flight takes off or lands in Austria. Domestic flights are recorded several times because the reported values of the individual airports are counted. The information on air freight transported refers to goods that were actually transported by aircraft. Data is collected and published monthly. Data on replacement air freight traffic (transport by lorry between airports) is also collected once a year.